Drill strings of pipe for oil and gas wells are assembled or disassembled vertically on a derrick one joint at a time, and are stored horizontally on pipe racks situated on the ground adjacent the rig. The work floor of the rig is typically elevated substantially above the pipe rack such that transferring sections of pipe to and from the work floor and the racks is necessary and requires careful handling of the heavy pipe to protect the workers and the pipe.
As shown in FIG. 1, a common prior art solution in the context of a transportable trailer is a pipe handling apparatus implementing a base supporting a pivoting boom having a pipe receiving trough along its upper surface. The boom has an upper end which can be placed adjacent to and raised to the height H of a derrick or rig floor (not shown), and a lower end which is movable along the base. Typically the lower end is guided in a cavity in the base which also serves to receive the boom therein when lowered. An arm pivots between the base and the boom for raising the boom from the base to the floor height. At the end of a pipe lowering operation, as well as during transport or storage, the boom is retracted to nest into the cavity.
Although effective to raise the upper end to a predetermined height H, this type of prior art pipe handling apparatus does not readily permit adaptation to raise the upper end to a range of different rig floor heights. A variety of other pipe handling systems are known, such as, for example, U.S. Pat. No. 4,371,302 to Frias et al., U.S. Pat. No. 6,533,519 to Tolomon et al., U.S. Pat. No. 7,163,367 to Handley, U.S. Pat. No. 7,021,880 to Morelli et al., U.S. Pat. No. 6,899,510 to Morelli et al. and Canada 2,224,638 to Handley et al., the entireties of each of which are incorporated herein by reference. However, these types of prior art pipe handling systems do not readily permit a variety of horizontal placements of the upper end of the boom, such as closer to, or further back from, a work floor of the rig.
There is a demonstrated needed for a pipe handling system wherein the boom can be raised to meet with a range of derrick or rig floor heights, as well as a range of horizontal positions relative to such derrick or rig floor, without the disadvantages of the prior art.